Aluminum PCB Manufacturing: Structure of Aluminum PCB
The copper-clad laminate (CCL) is the basis of the aluminum PCB
structure. It consists of the aluminum membrane, aluminum base,
dielectric layer, and the copper foil. In the picture below, you
can see the structure of the copper-clad laminate.
Copper Foil layer
The Aluminum CCL has the same copper foil layer as that of any
other type of PCC’s CCL. It is the current’s objective to provide a
large current carrying capacity. Due to this, choosing a thick
copper circuit is a good decision in aluminum PCB manufacturing.
Generally, the manufacturer prefers the thickness between 1oz to
10oz. It is important for the copper foil’s backside to go through
different oxidation treatment. The treatment involves chemicals as
well.
Likewise, the front side goes through brass plating and zincing.
The main reason for front treatment is to improve the peel-off
strength of the aluminum Printed Circuit Board.
Dielectric Layer
The next layer, is the dielectric layer. It compromises of a
composed thermal dielectric material. This material has a low
thermal resistance. Generally, it has a thickness ranging from 50μm
to 200μm. The thickness depends upon the type of the Printed
Circuit Board and the consumer’s demand.
This layer seems to be the aluminum Printed Circuit Board core
technology. It has the same functionality as that of the
anti-thermal aging. Moreover, it has the capacity to withstand
thermal stress as well as mechanical stress.
Aluminum Base Layer
When we say aluminum base layer, we actually mean the aluminum
substrate. This substrate is supporting all the components present
on the board. It binds the components to the board. It is
imperative for this substrate to be highly thermally conductive.
Base layer also needs to be suitable for the different mechanical
processes including cutting, punching, and drilling.
Base Membrane
The aluminum base pays an important role in the protection of PCB’s
aluminum surface. It ensures that the surface is safe from agent
etching and scraping. There are two main types of base membrane,
first ordinary and second anti-high temperature.
Ordinary membrane usually withstands temperature lower than 120°C.
On the contrary, the anti-high temperature can withstand up to
250°C.
The anti-high type is the best choice for hot air solder levelling.
